The present invention relates to means for recognizing speech. More particularly, it relates to a speech recognition system that enables characteristic patterns of the recognizable speech to be properly compared with the characteristic patterns of a plurality of previously registered speech patterns before both a match is obtained.
Conventional, speech recognization systems perform a matching operation using a DP matching method in relation to the characteristic patterns of the individual speech and the characteristic patterns of a plurality of the preliminarily registered individual speech patterns is carried out so that the speech can eventually be recognized in accordance with the result of carrying out the matching operation.
Nevertheless, if all the characteristic patterns of a plurality of the preliminarily registered individual speeches must be tested, either vastly complex calculations or high speed hardware will be necessary, and as a result, such a huge system becomes too costly.
To eliminate such an inconvenience, a proposal suggests to use either a so-called "preliminary selection" or an advance reference so as to limit the number of tests for the recognizable object by preliminarily selecting for comparison the easily calculatable patterns while using the DP matching method before.
Although such a preliminary selection can minimize the calculation requirements in the final matching operation, there is a constant demand for realizing a still more effective speech recognizing system capable of drastically minimizing such calculation requirements as well as the cost associated with these calculations.